so does a T-piece restrict flow, for example: if i have 2 PCV hoses from the intake rocker covers running to a T-piece then a catch-can. would that defeat the purpose of the 2 hoses seeing that it will meet in the middle and balance out into 1 hose HENCE restricting the flow???? this seems like a question for those who can get really technical and understand there answer because i keep thinking about it in my head and im stumped
From my understanding, its not under the intake plenum pressure - its more of a safety system to prevent the build up of air pressure in the block, which could lead to too much pressure in the sump, blowing out the dip stick and pushing oil out the crank seals. It has no impact on performance of the engine as such ...
Strictly speaking a T will always restrict flow. PCV flow is so small (assuming no busted rings etc) that it will be negligible in this application. In high volume liquid and gas flow tee's are pretty horrible when it comes to losses. Here is a overview of pipe losses: Clicky
If the combined flow rate of the two pipes merging into a single pipe is greater than the flow rate of the single pipe then flow will be restricted. The next question is why are there two hoses? Is it because they needed to vent from two different places or was it for flow or both. You could connect a spare boost gauge to the dipstick tube with a hose long enough to reach into the cabin and take the car for a drive to test your setup. If the gauge ever reads positive then you have a problem.
The factory hoses have a plug in them with what looks like a 3mm hole so i don't see how a larger diameter hose or T peice will cause problems
My VG has a similar engine breather setup to yours except that the two hoses run separately into the catch can. So no T piece. Mine is mainly a turbo race engine though so breathing is quite important so as to not pressurise the engine internally and push oil out through seals. If you have only one inlet into the catch can then all you can do is use a Y piece as bRacket suggested. It will help a bit.
I really can believe that this is actually a discussion point. Just connect the frikken hoses up and close the bonnet M8. E
Lol... he must have left the rings out of his motor..... He has so much blowby gas that he's worried about restriction at the hose connection Under all conditions except WOT, the hoses you're talking about carry a vacuum. So your setup would be drawing air from your catch can, which would make your single hose the possible restriction. At WOT the blowby gases will flow in the reverse direction (into the catch can), but in a healthy motor the pressure would amount to 3 poofteenths of SFA
AND, if the PCV valve is fitted and working, it acts as a checkvalve to prevent boost pressure from blowing backwards thru the system and pressurising the sump!!! E
who said i had blowby??? with all the parts in my engine i can put some extra time into the way it breaths as its crucial to get the right setup when this things goes on track at phillip island.
You are doing the right thing. To build a good track car requires attention to detail, something some people are not aware of apparently.
